The antigen-induced association of Lyn kinase with BCR. (A) CFP, YFP, Ea, and merged time-lapse images of CH27 B cells expressing LynFL-CFP and Igα-YFP 0–600 s after the encounter of either ICAM-1 alone or ICAM-1– and antigen-containing bilayers. CFP and YFP FIs and Ea across the contact area indicated by red lines (scale, 20 μm) are given. (B) Quantification of the Igα-YFP and LynFL-CFP FIs and Ea plotted against time for cells imaged in A.